National / Hartford Flat-Die

Hartford Image The following lesson outline details the tasks needed to be a machinist on a National or Hartford thread roller. Some of these tasks require the trainee to explain how something works to insure they have the required understanding of the processes and are not simply memorizing procedures. All of the tasks listed will be a part of the Performance Test within each lesson. To learn more about these tests and the training process itself, see the Philosophy section.

The instructional technique employed will enable individuals to learn to setup and operate the National / Hartford Thread Roller with little difficulty. The trainee will also learn the measurement techniques needed by thread roll setup operators to check quality. The last two lessons cover the I.T.W. Sems attachment and are optional. Both existing personnel and new trainees can utilize these training materials to develop or improve their performance.

Lesson 1: Basic Components [ Top ]

After completing this lesson the operator will be able to:

  1. Locate, identify and explain the purpose of the machine components which move the dies and perform the threading.
  2. Explain the threading movement cycle.
  3. Locate, identify and explain the purpose of the main drive components of the thread roller.
  4. Locate, identify and explain the purpose of the main components which feed blanks into the thread roller.
  5. Explain the operation of the Starter Finger during the threading cycle, and describe some common causes of jammed blanks.
  6. Locate, identify and explain the purpose of the main components of the Sems attachment.
  7. Explain the operation of the Sems attachment.

Lesson 2: Basic Controls and Operation [ Top ]

After completing this lesson the operator will be able to:

  1. Locate, identify and explain the purpose of the gauges, tanks and other components used for machine lubrication, and describe the correct levels in all sight gauges.
  2. Perform a complete lubrication on a thread roller, including inspecting sight gauges, adding lubricant and coolant as needed, and greasing all grease fittings.
  3. Locate, identify and explain the purpose of controls used to hand crank the machine.
  4. Remove a blank from the dies by hand-cranking.
  5. Locate, identify and explain the purpose of the controls and indicators used to jog the machine.
  6. Jog the machine.
  7. Load blanks and prepare the machine for operation, then start the machine into normal operation. After running some parts, properly stop normal operation.
  8. Locate, identify and explain the purpose of the controls on the Sems attachment.
  9. Jog the Sems attachment.
  10. Set all required controls to the proper settings, then start the Sems attachment into normal operation. Stop operation of the Sems attachment.

Lesson 3: Naming and Measuring Workpiece Features [ Top ]

After completing this lesson the operator will be able to:

  1. Locate and identify common features of blanks, and identify dimensions and angles which are commonly measured or checked.
  2. Check blanks for dimensional accuracy, including body length and diameter, overall length, and point diameter. The Operator will select the proper measuring instrument for each measurement.
  3. Identify common faults on blanks by visual inspection, including flashes, cracks and bent heads.
  4. Locate and identify major features and dimensions on threaded parts.
  5. Identify examples of common thread and point types on threaded fasteners.
  6. Locate and correctly read information from the thread notation on a part print, including Major Diameter, TPI, Thread Form and Series, and Class of Fit.
  7. Check threaded parts for dimensional accuracy using all proper measuring instruments and gauges.
  8. Measure pitch diameter on threaded parts using a tri-roll pitch gauge.
  9. Identify common faults on threaded parts by visual inspection.
  10. Measure and visually inspect washers for Sems assembly.

Lesson 4: Relieving The Dies [ Top ]

After completing this lesson the operator will be able to:

  1. Identify and explain the purpose of common types of die relief, and describe what type of die relief is required for common fastener head types.
  2. Describe the correct dimensions for die relief, including the unground starting end of the die.
  3. Grind the proper die relief on a set of dies for threading blanks with a flat bearing surface.
  4. Grind the proper radius relief on a set of dies.
  5. Grind the proper die relief on a set of dies for threading blanks with a tapered bearing surface.
  6. Determine the correct dimensions for relieved steel plates for blanks with a shoulder, to hold the blank head at the correct height above the threading dies.

Lesson 5: Installing The Dies [ Top ]

After completing this lesson the operator will be able to:

  1. Identify different types of threading dies, and describe the type of fasteners made with each type of die.
  2. Inspect and measure a blank and set of dies for a setup, and compare to the part print, to make sure that they are correct for the setup. This includes checking a fluting insert for a setup.
  3. Identify common types of die damage.
  4. Remove the dies and die packing from a machine in preparation for setup.
  5. Perform all required measurements and calculations, then select the proper die packing for the stationary die and moving die.
  6. Select die packing for both dies, if needed, to extend the thread forms beyond the machine feed rail.
  7. Install the stationary die and all appropriate die packing, seat the die, then install and tighten the top die clamps. Also install the end die clamp if used on that machine.
  8. Install and seat the moving die and die packing, then install and tighten the top die clamps.
  9. Locate, identify and explain the purpose of machine components used to adjust die squeeze.
  10. Rough adjust die squeeze until a blank fits snugly between the dies.

Lesson 6: The Blank Feed System [ Top ]

After completing this lesson the operator will be able to:

  1. Locate, identify and explain the purpose of components used to adjust the feed rails and the feed rail cover.
  2. Remove the feed rail cover, then adjust the feed rail width so that blanks slide down freely without falling off.
  3. Use a straight-edge to determine whether the feed rail height must be adjusted.
  4. Adjust the feed rail height until the feed rails are level with the top of the stationary die.
  5. Replace the feed rail cover, then center it over the feed rails.
  6. Adjust the height of the feed rail cover until it is just high enough, but no higher, to allow the blanks to slide freely down the feed rails without binding.
  7. Locate, identify and explain the purpose of the Guide Rails and the Guide Plate in the vibratory bowl.
  8. Adjust the Guide Rails and the Guide Plate in the vibratory bowl until blanks slide freely through them without falling off.
  9. Adjust the Holddown Finger until the pressure is just high enough, but no higher, than needed to allow the blanks to slide past it. Check the adjustment by jogging the machine.
  10. Turn on the machine, then adjust the feed control air lines until the vibratory bowl turns on and off at the proper times to control the flow of blanks.

Lesson 7: The Starter Finger [ Top ]

After completing this lesson the operator will be able to:

  1. Select an appropriate Starter Finger for a setup.
  2. Identify and explain the purpose of clearance angles and contours used on Starter Fingers for different types of blanks.
  3. Grind all required clearances and contours on a new Starter Finger, so that the ground, deburred Starter Finger fits a blank securely.
  4. Remove the Starter Finger Bracket and Starter Finger from the machine.
  5. Install the Starter Finger for a setup and replace the bracket. The Starter Finger, when in place, will be level with the top of the Stationary Die.
  6. (#10-400 Machine) Determine whether there is sufficient clearance between the end of the Starter Finger and the dies.
  7. Adjust the clearance between the Starter Finger and the dies by installing shims behind the pins on the Starter Finger Bracket, moving the Starter Finger toward the moving die or the stationary die.
  8. Locate, identify and explain the purpose of components used to adjust the retraction of the Starter Finger.
  9. Adjust the retracted position of the Starter Finger using the Starter Finger Turnbuckle.
  10. Adjust the retracted position of the Starter Finger using the Adjusting Slide.

Lesson 8: Adjusting The Dies [ Top ]

After completing this lesson the operator will be able to:

  1. Use a straight-edge to determine whether the die height must be adjusted.
  2. Adjust the die height by adding or changing shims under the moving die until the top surfaces of the dies are flush.
  3. Locate, identify and explain the purpose of components used to adjust Die Match.
  4. Make a blank for checking the Die Match by jogging a blank 1/2 of a turn into the dies, marking the blank head, then hand cranking the blank back out of the dies.
  5. Determine whether the moving die must be raised or lowered in order to properly adjust the Die Match. This will be done by visual inspection of the partially rolled, marked blank.
  6. Adjust the Die Match using the Eccentric until the dies are properly aligned.
  7. Check the clearance between the cutoff edges on Gimlet Point dies in a machine using shim stock.
  8. Fine adjust the Die Squeeze until the rolled threads are the proper major diameter, pitch diameter, roundness and thread sharpness.
  9. Identify and explain the cause of problems on thread-rolled parts, including gimlet point tail, blunt gimlet point, improper flute depth, and overtracked flutes.
  10. Install a fluting insert in the dies and adjust the flute depth.
  11. Correct overtracked flutes by having one flute at a time ground off of the fluting insert.

Lesson 9: Final Adjustment and Troubleshooting [ Top ]

After completing this lesson the operator will be able to:

  1. Locate, identify and explain the purpose of components used to perform final adjustments, including the air control flow, the machine speed, the air kickout, the Starter Finger air assists, the feed rail vibration, and the vibratory bowl adjustments.
  2. Begin final adjustments by turning the machine speed down as far as it will go.
  3. Adjust the air kickout so that the threaded parts are blown away from the stationary die as soon as they reach the end of the stationary die.
  4. Adjust the air assists so that the blanks remain parallel with the dies as they drop in front of the Starter Finger.
  5. Adjust the feed rail vibrator and the feed control air lines so that the blanks feed quickly down the feed rails.
  6. Adjust the vibratory bowl Control Plate to correct problem conditions with blank feeding.
  7. Adjust the vibration of the vibratory bowl to achieve the fastest possible blank feeding without feeding problems.
  8. Adjust the machine speed, and fine adjust the blank feeding system, to achieve the highest possible production rate without causing feeding or part problems.
  9. Identify and explain the cause(s) of die problem indicators.
  10. Identify and explain the cause(s) of threaded part problem indicators.
  11. Shim the dies to correct taper problems, including taper at the top of the threaded parts and at the bottom of the threaded parts.
  12. Determine where additional die relief is needed by applying layout ink to the tops of the dies, then jogging a few blanks through the dies.
  13. Explain the die helix angle, and describe the problem indicators which may be caused by an incorrect die helix angle.
  14. Perform the proper procedure to correct an incorrect die helix angle.

Lesson 10: Sems Assembly [ Top ]

After completing this lesson the operator will be able to perform the tasks necessary to setup and adjust any of three types of transfer assemblies commonly found on either Boltmakers or Progressive Headers including:

  1. Locate, identify and explain the purpose of the components of the Sems assembly.
  2. Describe the operation of the Sems assembly, including the assembly of the blanks and washers at the Transfer Point, and feeding of the assembled parts into the thread roller feed rails.
  3. Properly remove the Sems tooling from a previous setup, including: the assembly finger, the transfer finger, the blank disk guide clamps, the blank disk, the washer guide rails, the assembly disk and assembly guide, the bridge and fence, the washer disk, and the guide plates.
  4. Select the proper washer disk and guide plates, using a blank, a washer and the part print to determine the correct dimensions.
  5. Properly install the Sems guide plates.
  6. Check the guide plate heights, and adjust if necessary so that none of the guide plates is higher than the preceding one.
  7. Properly install the washer disk, using the large washer and the washer disk clamp to clamp the washer disk into place.
  8. Properly install the fence, with the opening at the bottom.
  9. Replace the bridge; use shims to raise the bridge if necessary so that the washers move freely under it.
  10. Select the proper washer guide rails, based on the fastener size.
  11. Install the washer guide rails and position so that a blank slides freely into the rails.
  12. Select the proper assembly disk and assembly guide, based on the fastener size, and install onto the Sems assembly.
  13. Select the proper blank disk, based on the fastener size; select an additional blank disk if required by the blank body length. Also select the required spacers if more than one blank disk is to be installed, based on the blank body length.
  14. Properly install the blank disk(s) and any required spacers.

Lesson 11: Sems Adjustment [ Top ]

After completing this lesson the operator will be able to:

  1. Locate, identify and explain the purpose of all air assists and adjustment controls on the Sems attachment.
  2. Adjust the height of the upper feed rails until they are flush with the blank disk.
  3. Install the blank disk guide; adjust the blank disk guide clamps until the blank disk guide is flush with the blank disk.
  4. Time the assembly disk by aligning it with the blank disk.
  5. Time the washer disk by aligning it with the blank disk, using the controls on the Sems assembly.
  6. Install and properly position the assembly finger and the transfer finger.
  7. Explain the operation of the Assembly Detector and the cover, and how they prevent unassembled blanks from dropping into the thread roller feed rails.
  8. Install the cover and the Pressure Finger, and adjust these components to prevent threading of unassembled blanks.
  9. Perform all required adjustments to the upper feed rails: the feed rail width, the height and centering of the feed rail cover, and the holddown finger.
  10. Adjust the assembly detector air assists to kick all unassembled blanks into the discharge chute.11. Adjust the washer disk air assists to remove all excess washers and all upside-down washers.
  11. Fine adjust the timing of the washer disk with the Sems in operation.
  12. Adjust the transfer air assists to remove any blank and washer assemblies which become jammed on the assembly detector.
  13. Adjust the starter finger air assists, the feed rail air assists and the feed control air lines.
  14. Adjust the electric eye on the feed rails for proper stopping and starting of the Sems attachment.
  15. Start up the thread roller and the Sems attachment into operation; perform all final adjustments which are needed for efficient operation and high production rate.